Unveiling the Therapeutic Potential of Dulaglutide in Mitigating Tacrolimus-Induced Nephrotoxicity Through Targeting the miR-22/HMGB-1/TLR4/MyD88/NF-κB Trajectory

Abstract

Tacrolimus (Tac) is an immunosuppressive drug used to reduce the risk of allograft rejection; however, it can induce renal injury. High mobility group box 1 (HMGB-1) protein, which induces inflammation through the aberrant stimulation of the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response protein (MyD88)/nuclear factor kappa B (NF-κB) trajectory, could represent a molecular target for alleviating Tac-induced renal damage. The present study aimed to investigate the potential protective role of the GLP-1 agonist, dulaglutide (Dula), against Tac-induced nephrotoxicity in rats. Rats were administered Tac (5 mg/kg/day) and vehicle or Dula (0.2 mg/kg once a week) for 14 days. Treatment with Dula reduced serum creatinine plus blood urea nitrogen and attenuated Tac-induced renal histopathological changes. Dula treatment also hampered renal inflammation and restored redox homeostasis, as indicated by remarkably reduced tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), and NADPH oxidase 1 levels alongside marked replenishment in reduced glutathione (GSH) content. These effects were mediated through the upregulation of miR-22 expression and the consequent inhibition of the HMGB-1/TLR4/MyD88/NF-κB trajectory. Collectively, Dula has been demonstrated to protect rats against Tac-induced nephrotoxicity by reducing inflammation, restoring redox homeostasis, and modulation of the miR-22/HMGB-1/TLR4/MyD88/NF-κB trajectory. Dula may be beneficial clinically in preventing Tac-induced renal injury.

Keywords: HMGB‐1; TLR4; dulaglutide; miR‐22; nephrotoxicity; tacrolimus.

Figure 1

Influence of Dula treatment on renal function in the Tac‐treated rats; (a) BUN and (b) Scr. Values were expressed as mean ± S.D. (six rats/group). **p < 0.01, ***p < 0.005, ****p < 0.001, ns = no significance. Dula, Dulaglutide; Tac, tacrolimus.

Figure 2

Effect of Dula treatment on inflammatory markers in the Tac‐treated rats: (a) NF‐kB p65, (b) TNF‐α, and (c) IL‐1β. Values were expressed as mean ± S.D. (n = 6 rats in each group). Statistical analysis was performed using one‐way ANOVA followed by Turkey's Multiple Comparisons test. ***p < 0.005, ****p < 0.001, ns = no significance. Dula, Dulaglutide; Tac, tacrolimus.

Figure 3

Effect of Dula treatment on oxidative stress biomarkers in the Tac‐treated rats: (a) NOX‐1, (b) MDA, and (c) GSH in the Tac‐provoked animals. Values were expressed as mean ± S.D. (six rats/group). Statistical analysis was performed using one‐way ANOVA followed by Turkey's Multiple Comparisons test. *p < 0.05, **p < 0.01, ****p < 0.001, ns = no significance. Dula, Dulaglutide; Tac, tacrolimus.

Figure 4

Influence of Dula treatment on expression of (a) miR‐22, (b) HMGB‐1, (c) TLR4, and (d) MyD88 in the Tac‐treated animals. Values were expressed as mean ± S.D. (six rats/group for RT‐PCR and three rats/group for W.B.). Statistical analysis was performed using one‐way ANOVA followed by Turkey's Multiple Comparisons test. *p < 0.05, ***p < 0.005, ****p < 0.001, ns = no significance. Dula, Dulaglutide; Tac, tacrolimus.

Figure 5

Effect of Dula treatment on Tac‐induced histopathological alterations. Sections (a and b) control and (c and d) Dula revealed almost intact, well‐organized morphological characteristics of renal parenchyma with abundant records of apparent intact nephron segments with mostly preserved tubular epithelium (arrow), minimal evidence of degenerated tubular epithelial cells, intact renal corpuscles (star), and intact vasculatures. In contrast, sections of Tac (e and f) revealed focal figures of tubular vacuolar degenerative changes records at cortical and corticomedullary zone segments (black arrow) accompanied with mild tubular dilation (star) as well as mild interstitial mononuclear inflammatory cells infiltrates were shown (red arrow). In contrast, sections of the Dula‐treated rats (g and h) showed significant renoprotective potential evidenced by intact nephron segments epithelium with preserved integrity (black arrow), minimal sporadic degenerative changes (red arrow) without abnormal tubular dilatations or inflammatory infiltrates.